Until recently, the elements were arranged in order of their atomic mass atomic number names (alphabetically)( atomic mass, atomic number, names (alphabetically) ).
What were the problems with Newlands' Law of Octaves?
The groups contains elements that didn't have similar properties e.g. C and Ti
He mixed up metals and non-metals e.g. O and Fe
He didn't leave any gaps for undiscovered elements
They weren't arranged in order of atomic mass
They went against the Church
Group 1 metals become ❌ reactive as you go down the group because the outer electron is more easily lost as it's further from the nucleus.
Label the halogen with the dot.
Transition metals are less reactive, denser, stronger and harder than Group 1 metals
Permanent hardness is caused by calcium sulphate hydrogencarbonate ions sodium hydroxide( calcium sulphate, hydrogencarbonate ions, sodium hydroxide ).
Which of these is the order water is treated in?
Screening, removal of solids and microbes, filtration and chlorination
Filtration, screening, chlorination, removal of solids and microbes
Removal of solids and microbes, filtration, chlorination and screening
Equilibrium means the amounts of reactants and products reach a certain balance and stay there.
If you raise the pressure, it will encourage the reaction which produces ❌ volume.
What conditions are needed for the Haber Process?
Pressure: 200 atm
Temperature: 450 degrees C
Catalyst : Iron
Pressure: 900 atm
Temperature: 20 degrees C
Catalyst: Magnesium
Alcohols have the functional -OH -COOH -COO-( -OH, -COOH, -COO- ) group.
The first 3 alcohols...
Dissolve completely in water to form neutral solutions
React with sodium to give hydrogen & alkoxides
React with carboxylic acids to form an ester + water
Don't react with anything
Are used as fuels and solvents
Are poisonous
Carboxylic acids don't ionise completely (release H+ ions) and so form weak acidic strong acidic weak alkaline strong alkaline( weak acidic, strong acidic, weak alkaline, strong alkaline ) solutions.
How do you work out concentration?
Moles / Volume
Moles * Volume
Mass / Relative Formula Mass
In an exothermic reaction, the energy released in bond formation is than the energy used in breaking old bonds.
What are the problems with using hydrogen fuel cells?
Hydrogen is gas - takes up more space to store
It's very explosive - difficult to store safely
Hydrogen fuel is usually made from hydrocarbons or electrolysis of water - fossil fuels & electricity
They produce pollutants
They don't produce much power
Aluminium hydroxide is a white precipitate at first but redissolves in excess NaOH to form a ❌ solution.
To test for halide ions, add dilute nitric acid followed by ❌.
To test for a sulphate ion, add dilute HCl followed by barium chloride solution silver nitrate solution nitric acid( barium chloride solution, silver nitrate solution, nitric acid ).
A more reactive halogen can displace a less reactive halogen from an aqueous solution of its salt.
Por favor espera - en proceso…